Brazilian mixed martial artist Luiz de Franca, a fighter who trained with the Kimura Nova Uniao team, was murdered inside a gym Monday in Natal, Brazil (h/t MMA Fighting). The cause of death was determined to be several gunshot wounds.

Right now, the main suspect in the case is a former police officer who used to train at the Alta Performance Gym, where de Franca worked as a teacher. He was removed from the gym in late January because he had allegedly become "too violent" in training.

The suspect has reportedly suffered from depression in the past but been of a sound mind recently, which clouds things up even more.

Image via Wanderlei Silva's Facebook

Luiz de Franca in one of his MMA bouts.

De Franca, a teammate of UFC fighters Jussier da Silva and Ronny Markes, was an undefeated welterweight at 3-0, according to Sherdog. He made his pro debut in 2012 after an 0-2 stint as an amateur.

All three of his wins were finishes—two by submission and one by TKO. De Franca's most recent win came over Jefferson Silva, whom de Franca tapped out with a second-round armbar.

MMA great Wanderlei Silva, who trained with de Franca in Las Vegas in 2012, left the following message on his Facebook page, which was translated by MMA Fighting: "I'm really sad. Luiz de Franca, who trained with us in Las Vegas for almost a year, was brutally murdered this Monday morning in Natal. He was only 25 and never got himself in trouble. He was a good kid."

This tragedy has obviously rocked the Brazilian community, as well as the MMA community as a whole. Luckily for police, the crime was caught on tape for them to investigate. Hopefully, following examination of the footage, an arrest will happen in short order.